Welcome! Today we're going to learn about fractions. A fraction is a way to talk about parts of a whole. Imagine you have a delicious pizza! This whole pizza represents one whole thing. We can write this as the fraction one over one. The number on top, called the numerator, tells us how many parts we're talking about. The number on the bottom, called the denominator, tells us how many equal parts make up the whole.
Now, let's cut our pizza into equal parts. When we cut something into equal parts, each part is exactly the same size. Here, we've cut our pizza into 4 equal parts. The bottom number of our fraction, called the denominator, tells us how many equal parts we've cut the whole into. So the denominator here is 4. If we have all 4 pieces, that's still the whole pizza, so we can write this as four-fourths, which equals one whole.
Now, let's talk about taking some slices of our pizza. The top number of a fraction, called the numerator, tells us how many parts we have or are talking about. If we take just one slice out of our four equal slices, we write this as one-fourth. The 1 on top means we have 1 slice, and the 4 on the bottom means the whole pizza was cut into 4 equal parts. So one-fourth means 1 out of 4 equal parts.
We can have different fractions depending on how many parts we take. If we take 1 slice out of 4, we have one-fourth of the pizza. If we take 2 slices out of 4, we have two-fourths of the pizza, which is the same as one-half. If we take 3 slices out of 4, we have three-fourths of the pizza. The numerator changes based on how many slices we take, while the denominator stays the same because the total number of slices doesn't change.
Let's wrap up what we've learned about fractions. A fraction shows parts of a whole. The bottom number, called the denominator, tells us the total number of equal parts. The top number, called the numerator, tells us how many parts we have. We use fractions every day in real life! When you eat half of a cookie, that's one-half or one out of two equal parts. When someone says 'quarter past three,' they mean it's three and one-fourth of an hour, or 15 minutes past three. When you're baking and need three-fourths cup of milk, you're using fractions too! Fractions help us share things fairly and measure parts of a whole.